1. Field of the Invention
The present invention generally relates to a cell press and a method of forming a photovoltaic cell module with the use of a cell press.
2. Description of the Related Art
Solar or photovoltaic cells are semiconductor devices used to convert light into electricity. In many applications, the photovoltaic cells are encapsulated to form photovoltaic cell modules (hereinafter referred to as “modules”) to provide additional protection for the photovoltaic cell from environmental factors such as wind and rain. To date, however, encapsulation methods known in the art have been expensive and time consuming and, in many cases, ineffective.
The photovoltaic cells are typically encapsulated with the use of a cell press. The photovoltaic cell and a substrate with a tie layer disposed on the substrate are placed in the cell press. The cell press contacts the photovoltaic cell with the tie layer to encapsulate the photovoltaic cell with the tie layer. The cell press applies pressure to the photovoltaic cell to place the photovoltaic cell on the tie layer, partially encapsulated by the tie layer, or fully encapsulated by the tie layer.
When the photovoltaic cell contacts the tie layer, air bubbles become trapped between the photovoltaic cell and the tie layer. These air bubbles are disadvantageous in that the air bubbles make the module susceptible to the environment. In addition, these air bubbles reduce the light absorbing capability of the module. By applying pressure to the photovoltaic cell, the plate squeezes out some of the air bubbles between the photovoltaic cell and the tie layer. However, the application of pressure to the photovoltaic cell does not remove all of the air bubbles between the photovoltaic cell and the tie layer if the tie layer is a liquid or does not have sufficient tack or penetration to allow it to conform or remain in contact with the tie layer, which results in the disadvantages previously described. In addition, to remove any considerable amount of air bubbles, the pressure must be applied to the photovoltaic cell for a substantial amount of time while the air bubbles slowly flow out from between the photovoltaic cell and the tie layer which makes for a slower process and therefore may not be cost effective. In other words, the requirement that pressure must be applied to the photovoltaic cell increases the cycle time for the production of the module, which is obviously undesirable from a manufacturing standpoint because fewer modules can be assembled in a given amount of time. As such, the application of pressure to remove the air bubbles from between the photovoltaic cell and the tie layer is disadvantageously ineffective and time consuming.
Accordingly, there remains an opportunity to develop a cell press and a method of forming the module that eliminates air bubbles between the photovoltaic cell and the tie layer. There also remains an opportunity to develop a cell press and a method of forming a module in a time efficient and cost effective manner.